Storage-based Snapshots for KVM VMs (#3724)

* VM snapshots of running KVM instance using storage providers plugins for disk snapshots

Added new virtual machine snapshot strategy which is using storage providers plugins to take/revert/delete snapshots.
You can take VM snapshot without VM memory on KVM instance, using storage providers implementations for disk snapshots.
Also revert and delete is added as functionality. Added Thaw/Freeze command for KVM instance.
The snapshots will be consistent, because we freeze the VM during the snapshotting. Backup to secondary storage is executed after
thaw of the VM and if it is enabled in global settings.

* Removed duplicated functionality

Set few methods in DefaultVMSnapshotStrategy to protected to reuse them
without duplicating the code. Remove code that is actualy not needed

* Added requirements in global setting kvm.vmstoragesnapshot.enabled

Added more information in kvm.vmstoragesnapshot.enabled global setting,
that it needs installation of:
- qemu version 1.6+
- qemu-guest-agent installed on guest virtual machine

when the option is enabled

* Added Apache license header

* Removed commented code

* If "kvm.vmstoragesnapshot.enabled" is null should be considered as false

* removed unused imports, replaced default template

Removed unused imports which causing failures and replaced template to
CentOS8

* "kvm.vmstoragesnapshot.enabled" set to dynamic

* Getting status of freeze/thaw commands not the return code

Will chacke the status if freeze/thaw of Guest VM succeded, rather than
looking for return code. Code refactoring

* removed "CreatingKVM" VMsnapshot state and events related to it

* renamed AllocatedKVM to AllocatedVM

the states should not be associated to a hypervisor type

* loggin the result of "drive-backup" command

* Check which VM snapshot strategy could handle the vm snapshots

gets the best match of VM snapshot strategy which could handle the vm
snapshots on KVM.
Other storage plugins could integrate with this functionality to support group snapshots

* Added poolId in canHandle for KVM hypervisors

Added poolId into canHandle method used to check if all volumes are on
the same PowerFlex's storage pool

* skip smoke tests if the hypervisor's OS type is CentOS

This PR works with functionality included in qemu-kvm-ev which
does not come by default on CentOS. The smoke tests will be skipped if
the hypervisor OS is CentOS

* Added missed import in smoke test

* Suggested change to use ` org.apache.commons.lang.StringUtils.isNotBlank`

* Fix getting device on Ubuntu

On Ubuntu the device isn't provided and we have to get it from
node-name parameter. For drive-backup command (for Ubuntu) is needed and job-id which
is the value of node-name (this extra param works on Ubuntu and CentOS as well).

* Removed new snapshot states and functionality for NFS

* throw CloudRuntimeException

provide a properer error message when delete VM snapshot fails

* exclude GROUP snapshots when listing snapshots

* Skip tests if there is pool with NFS/Local

* address comments

Author: slavkap

api/src/main/java/com/cloud/storage/Snapshot.java

@@ -26,7 +26,7 @@
 
 public interface Snapshot extends ControlledEntity, Identity, InternalIdentity, StateObject<Snapshot.State> {
     public enum Type {
-        MANUAL, RECURRING, TEMPLATE, HOURLY, DAILY, WEEKLY, MONTHLY;
+        MANUAL, RECURRING, TEMPLATE, HOURLY, DAILY, WEEKLY, MONTHLY, GROUP;
         private int max = 8;
 
         public void setMax(int max) {

core/src/main/java/com/cloud/agent/api/FreezeThawVMAnswer.java

@@ -0,0 +1,39 @@
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+//
+
+package com.cloud.agent.api;
+
+public class FreezeThawVMAnswer extends Answer {
+
+    public FreezeThawVMAnswer() {
+        super();
+    }
+
+    public FreezeThawVMAnswer(FreezeThawVMCommand command, boolean success, String details) {
+        super(command, success, details);
+    }
+
+    public FreezeThawVMAnswer(FreezeThawVMCommand command, Exception e) {
+        super(command, e);
+    }
+
+    public FreezeThawVMAnswer(FreezeThawVMCommand command) {
+        super(command);
+    }
+}

core/src/main/java/com/cloud/agent/api/FreezeThawVMCommand.java

@@ -0,0 +1,56 @@
+//
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+//
+
+package com.cloud.agent.api;
+
+public class FreezeThawVMCommand extends Command{
+
+    public static final String FREEZE = "frozen";
+    public static final String THAW = "thawed";
+    public static final String STATUS = "status";
+
+    private String vmName;
+    private String option;
+
+    public FreezeThawVMCommand(String vmName) {
+        this.vmName = vmName;
+    }
+
+    public String getVmName() {
+        return vmName;
+    }
+
+    public void setVmName(String vmName) {
+        this.vmName = vmName;
+    }
+
+    public String getOption() {
+        return option;
+    }
+
+    public void setOption(String option) {
+        this.option = option;
+    }
+
+    @Override
+    public boolean executeInSequence() {
+        return false;
+    }
+
+}

engine/api/src/main/java/org/apache/cloudstack/engine/subsystem/api/storage/StorageStrategyFactory.java

@@ -36,4 +36,12 @@ public interface StorageStrategyFactory {
 
     VMSnapshotStrategy getVmSnapshotStrategy(VMSnapshot vmSnapshot);
 
+    /**
+     * Used only for KVM hypervisors when allocating a VM snapshot
+     * @param vmId the ID of the virtual machine
+     * @param snapshotMemory for VM snapshots with memory
+     * @return VMSnapshotStrategy
+     */
+    VMSnapshotStrategy getVmSnapshotStrategy(Long vmId, Long rootPoolId, boolean snapshotMemory);
+
 }

engine/api/src/main/java/org/apache/cloudstack/engine/subsystem/api/storage/VMSnapshotStrategy.java

@@ -29,6 +29,14 @@ public interface VMSnapshotStrategy {
 
     StrategyPriority canHandle(VMSnapshot vmSnapshot);
 
+    /**
+     * Used only for KVM hypervisors when allocating a VM snapshot
+     * @param vmId the ID of the virtual machine
+     * @param snapshotMemory for VM snapshots with memory
+     * @return StrategyPriority
+     */
+    StrategyPriority canHandle(Long vmId, Long poolId, boolean snapshotMemory);
+
     /**
      * Delete vm snapshot only from database. Introduced as a Vmware optimization in which vm snapshots are deleted when
      * the vm gets deleted on hypervisor (no need to delete each vm snapshot before deleting vm, just mark them as deleted on DB)

engine/storage/snapshot/src/main/java/org/apache/cloudstack/storage/vmsnapshot/DefaultVMSnapshotStrategy.java

@@ -53,6 +53,7 @@
 import com.cloud.storage.GuestOSHypervisorVO;
 import com.cloud.storage.GuestOSVO;
 import com.cloud.storage.VolumeVO;
+import com.cloud.storage.Storage.ImageFormat;
 import com.cloud.storage.dao.DiskOfferingDao;
 import com.cloud.storage.dao.GuestOSDao;
 import com.cloud.storage.dao.GuestOSHypervisorDao;
@@ -67,6 +68,7 @@
 import com.cloud.utils.exception.CloudRuntimeException;
 import com.cloud.utils.fsm.NoTransitionException;
 import com.cloud.vm.UserVmVO;
+import com.cloud.vm.VirtualMachine.State;
 import com.cloud.vm.dao.UserVmDao;
 import com.cloud.vm.snapshot.VMSnapshot;
 import com.cloud.vm.snapshot.VMSnapshotVO;
@@ -332,7 +334,7 @@ private void updateVolumePath(List<VolumeObjectTO> volumeTOs) {
         }
     }
 
-    private void publishUsageEvent(String type, VMSnapshot vmSnapshot, UserVm userVm, VolumeObjectTO volumeTo) {
+    protected void publishUsageEvent(String type, VMSnapshot vmSnapshot, UserVm userVm, VolumeObjectTO volumeTo) {
         VolumeVO volume = volumeDao.findById(volumeTo.getId());
         Long diskOfferingId = volume.getDiskOfferingId();
         Long offeringId = null;
@@ -350,7 +352,7 @@ private void publishUsageEvent(String type, VMSnapshot vmSnapshot, UserVm userVm
                 volumeTo.getSize(), VMSnapshot.class.getName(), vmSnapshot.getUuid(), details);
     }
 
-    private void publishUsageEvent(String type, VMSnapshot vmSnapshot, UserVm userVm, Long vmSnapSize, Long virtualSize) {
+    protected void publishUsageEvent(String type, VMSnapshot vmSnapshot, UserVm userVm, Long vmSnapSize, Long virtualSize) {
         try {
             Map<String, String> details = new HashMap<>();
             if (vmSnapshot != null) {
@@ -449,4 +451,20 @@ public boolean deleteVMSnapshotFromDB(VMSnapshot vmSnapshot, boolean unmanage) {
         }
         return vmSnapshotDao.remove(vmSnapshot.getId());
     }
+
+    @Override
+    public StrategyPriority canHandle(Long vmId, Long rootPoolId, boolean snapshotMemory) {
+        UserVmVO vm = userVmDao.findById(vmId);
+        if (vm.getState() == State.Running && !snapshotMemory) {
+            return StrategyPriority.CANT_HANDLE;
+        }
+
+        List<VolumeVO> volumes = volumeDao.findByInstance(vmId);
+        for (VolumeVO volume : volumes) {
+            if (volume.getFormat() != ImageFormat.QCOW2) {
+                return StrategyPriority.CANT_HANDLE;
+            }
+        }
+        return StrategyPriority.DEFAULT;
+    }
 }

engine/storage/snapshot/src/main/java/org/apache/cloudstack/storage/vmsnapshot/ScaleIOVMSnapshotStrategy.java

@@ -37,6 +37,7 @@
 import org.apache.cloudstack.storage.datastore.db.StoragePoolVO;
 import org.apache.cloudstack.storage.datastore.util.ScaleIOUtil;
 import org.apache.cloudstack.storage.to.VolumeObjectTO;
+import org.apache.commons.collections.CollectionUtils;
 import org.apache.log4j.Logger;
 
 import com.cloud.agent.api.VMSnapshotTO;
@@ -47,6 +48,7 @@
 import com.cloud.server.ManagementServerImpl;
 import com.cloud.storage.DiskOfferingVO;
 import com.cloud.storage.Storage;
+import com.cloud.storage.Storage.ImageFormat;
 import com.cloud.storage.VolumeVO;
 import com.cloud.storage.dao.DiskOfferingDao;
 import com.cloud.storage.dao.VolumeDao;
@@ -105,6 +107,13 @@ public StrategyPriority canHandle(VMSnapshot vmSnapshot) {
             throw new CloudRuntimeException("Failed to get the volumes for the vm snapshot: " + vmSnapshot.getUuid());
         }
 
+        if (!VMSnapshot.State.Allocated.equals(vmSnapshot.getState())) {
+            List<VMSnapshotDetailsVO> vmDetails = vmSnapshotDetailsDao.findDetails(vmSnapshot.getId(), "SnapshotGroupId" );
+            if (CollectionUtils.isEmpty(vmDetails)) {
+                return StrategyPriority.CANT_HANDLE;
+            }
+        }
+
         if (volumeTOs != null && !volumeTOs.isEmpty()) {
             for (VolumeObjectTO volumeTO: volumeTOs) {
                 Long poolId  = volumeTO.getPoolId();
@@ -118,6 +127,27 @@ public StrategyPriority canHandle(VMSnapshot vmSnapshot) {
         return StrategyPriority.HIGHEST;
     }
 
+    @Override
+    public StrategyPriority canHandle(Long vmId, Long rootPoolId, boolean snapshotMemory) {
+        if (snapshotMemory) {
+            return StrategyPriority.CANT_HANDLE;
+        }
+        List<VolumeObjectTO> volumeTOs = vmSnapshotHelper.getVolumeTOList(vmId);
+        if (volumeTOs == null || volumeTOs.isEmpty()) {
+            return StrategyPriority.CANT_HANDLE;
+        }
+
+        for (VolumeObjectTO volumeTO : volumeTOs) {
+            Long poolId = volumeTO.getPoolId();
+            Storage.StoragePoolType poolType = vmSnapshotHelper.getStoragePoolType(poolId);
+            if (poolType != Storage.StoragePoolType.PowerFlex || volumeTO.getFormat() != ImageFormat.RAW || poolId != rootPoolId) {
+                return StrategyPriority.CANT_HANDLE;
+            }
+        }
+
+        return StrategyPriority.HIGHEST;
+    }
+
     @Override
     public VMSnapshot takeVMSnapshot(VMSnapshot vmSnapshot) {
         UserVm userVm = userVmDao.findById(vmSnapshot.getVmId());